• Title/Summary/Keyword: Conservatism

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Creating Shared Value from Collaborative Logistics Systems: The Cases of ES3 and Flexe

  • Namchul Shin
    • Asia pacific journal of information systems
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    • v.30 no.1
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    • pp.214-228
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    • 2020
  • Shared value enhances the competitiveness of a company while simultaneously reducing societal burdens. By allowing companies to share their resources, collaborative logistics systems provide companies with an opportunity to create shared value, namely, not only economic value by enhancing the utilization of resources, but also social value by reducing energy consumptions and greenhouse gas emissions associated with logistics and transportation. Emerging businesses, such as ES3 and Flexe, have recently demonstrated how they created shared value through collaborative logistics services, for example, ES3's collaborative warehousing and direct-to-store (D2S) program, and Flexe's on-demand warehousing platform. However, the development of collaborative logistics systems is currently at a nascent stage. There are quite a few socio-technical barriers to overcome for sharing resources (data as well as infrastructure). Drawing on the socio-technical approach, this research examines how companies create both economic and social value from collaborative logistics systems. We highlight socio-technical barriers, particularly one set of social barriers, that is, competition-oriented conservatism prevalent among companies. Using the case study methodology and interview data, we closely investigate ES3 and Flexe, which provide collaborative logistics services, and demonstrate how technical and social barriers are addressed to create shared value from collaborative logistics systems.

Considerations on Screening for the Input Data of the Biosphere Model in the Radioactive Waste Disposal Facility (방사성폐기물 처분시설에서 생태계 모델의 입력데이터 선정에 대한 고찰)

  • Mi-Seon Jeong;Dong-Kuk Park;Soo-Gin Kim;Kang-Il Jung
    • Journal of Radiation Industry
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    • v.17 no.2
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    • pp.209-217
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    • 2023
  • The biosphere has important function in the safety assessment of a radioactive waste disposal facility. A biosphere model in the safety assessment needs various input data that contain significantly inherent uncertainties. This paper reviews the effects of the input data on the radiological impact assessment from main radionuclides such as 14C and 99Tc in the biosphere model. In addition, it is confirmed that the safety criteria is met, when the conservative input data for the intake rate, soil to plant concentration ratio, and distribution coefficients of the radionuclides are applied and probabilistic analysis are conducted in the biosphere model. Nevertheless, it is required to generate site-specific input data for the confidence building and reduce excessive conservatism in the biosphere model.

Optimal Cycle Length of MAGNOX Reactor for Weapons-Grade Plutonium Production

  • Seongjin Jeong;Jinseok Han;Hyun Chul Lee
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.22 no.2
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    • pp.219-226
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    • 2024
  • Democratic People's Republic of Korea (DPRK) has produced weapon-grade plutonium in a graphite-moderated experimental reactor at the Yongbyon nuclear facilities. The amount of plutonium produced can be estimated using the Graphite Isotope Ratio Method (GIRM), even without considering specific operational histories. However, the result depends to some degree on the operational cycle length. Moreover, an optimal cycle length can maximize the number of nuclear weapons made from the plutonium produced. For conservatism, it should be assumed that the target reactor was operated with an optimal cycle length. This study investigated the optimal cycle length using which the Calder Hall MAGNOX reactor can achieve the maximum annual production of nuclear weapons. The results show that lower enrichment fuel produced a greater number of critical plutonium spheres with a shorter optimal cycle length. Specifically, depleted uranium (0.69wt%) produced 5.561 critical plutonium spheres annually with optimal cycle lengths of 251 effective full power days. This research is crucial for understanding DPRK's potential for nuclear weapon production and highlights the importance of reactor operational strategy in maximizing the production of weapons-grade plutonium in MAGNOX reactors.

Analysis of Loss of Offsite Power Transient Using RELAP5/MOD1/NSC; II: KNU1 Design-Base Simulation (RELAP5/MOD1/NSC를 이용한 원자력 1호기 외부전원상실사고해석;II:설계기준사고)

  • Kim, Hyo-Jung;Chung, Bub-Dong;Lee, Young-Jin;Kim, Jin-Soo
    • Nuclear Engineering and Technology
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    • v.18 no.3
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    • pp.175-182
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    • 1986
  • The KNUI (Korea Nuclear Unit 1) loss of offsite power transient as a design-base accident has been simulated using the RELAP5/MOD1/NSC computer code. The analysis is carried out using the best-estimate methodology, but the sequence and its assumptions are based on the evaluation methodology th at emphasizes conservatism. Important thermal-hydraulic parameters such as average temperature, steam generator level and pressurizer water volume are compared with the results in the KNU1 Final Safety Analysis Report (FSAR). The present analysis gives much lower RCS average temperature and pressurizer water volume, and much higher S/G water volume at the turnaround point, which may be considered to be additional improved safety margins. This is expected since the present analysis deals with the best-estimate thermal-hydraulic models as well as the initial conditions on a best-estimate basis. These additional safety margins may contribute to further validate the safety of the KNU1 in this type of accidents(Decrease in Heat Removal by the Secondary System).

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The Research Regarding Cheong-Sam Pattern of Fabric Design in the Period of the Republic of China(1912-1949) - Comparison Between Jing Pai and Hai Pai - (중국 민국시대(1912년-1949년)에 나타난 치파오 문양에 관한 연구 - 경파이 치파오와 해파이 치파오의 문양 비교를 중심으로 -)

  • Seo, A-Jeong;Oh, Hee-Kyoung;Kim, Sook-Jin
    • Journal of the Korea Fashion and Costume Design Association
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    • v.15 no.3
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    • pp.69-83
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    • 2013
  • Clothes show not just the different social status of people, but the ideology and value of former society through pattern, colour, materials, shapes, etc. The purpose of this article is to fill the academic blank of this part by researching the pattern of fabric design in Jing Pai(Beiing style) and Hai Pai(Shanghai style) cheong-sam during the period of the Republic of China. The contrastive analysis of regional pattern between Jing Pai and Hai Pai cheong-sam expect to provide the theoretical basis for the former fashion designers and scholars. There are three approaches in the article: Data collection method, comparison method and Combining theory with practice method as film. Regarding components of pattern, both Jing Pai and Hai Pai cheong-sam have mostly single or composite pattern like plants. Further the most of Jing Pai cheong-sam pattern is traditional flower pattern. But Haipai cheong-sam patterns have some western flower pattern. Beside that, it have some geometry pattern. Regarding arrangement of the pattern, both cheong-sams have scattered dot style, the border style, and pictures style. But continuous type of Jing Pai cheong-sam is less while Hai Pai cheong-sam is the most. Comparing Jing Pai cheong-sam color of patterns in "Moment in Peking" is unadorned and types are simple as chinese traditional clothes; However, "In the Mood for Love" introduces us various material colors, new types of patterns and extraneous characteristic geometry patterns of Hai Pai cheong-sam. Generally speaking, the main characteristic of Jing Pai cheong-sam is traditional and conservatism. It keeps Chinese traditional pattern and culture to the most extent. However, Hai Pai cheong-sam are confluent and open with absorbed external culture and techniques which are endowed new artistic color.

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A Study on the Evaluation of Fracture Resistance Characteristics of Large Pipe by using the Curved CT Specimen (대형배관의 Curved CT 시편을 이용한 파괴저항특성평가에 관한 연구)

  • Kim, Ik Hyun;Shin, In Hwan;Park, Kweon Tae;Hong, Suk Woo;Park, Seon Soon;Yoon, Seon Hyun;Koo, Jae Mean;Seok, Chang Sung
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.7
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    • pp.623-626
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    • 2014
  • The LBB (Leak Before Break) concept is based on evaluating the fracture toughness. NUREG 1061, Vol.3 announced that the specimen for evaluating fracture resistance needs to have same thickness or thicker than pipe. Therefore, it is difficult to collect specimen from pipe which has same thickness as a pipe. So, ASTM standard suggested the use of standard specimen with 1 inch thickness. However, it has been known that an application of LBB by test results of standard specimen is conservative compare with that by real pipe. In this study, to supplement such conservatism, the evaluation of fracture resistance characteristics was performed with curved CT specimen, which has same thickness and curvature as a pipe. In addition, fracture resistance characteristics of curved CT specimen were compared with those of CT specimen. For this, shape factor F, hpl and g were obtained from FEM analysis using the limit load method.

A Study on Complement of the Design and Analysis Procedures of Friction Pendulum System (마찰진자형 면진받침의 설계 및 해석절차 보완에 관한 연구)

  • Kim, Hyun-Uk;Joo, Kwang-Ho;Noh, Sang-Hoon;Song, Jong-Keol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.1
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    • pp.488-494
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    • 2014
  • Although friction pendulum system has various advantages it is difficult to estimate the behavior because of velocity, bearing pressure, and temperature dependent characteristics of coefficient of friction. This research focuses on evaluating the conservatism of each method used and the effects of bearing pressure on the behavior of the system by conducting comprehensive examination on design and analytic procedure of friction pendulum system, as is proposed in standard, code and literature. In addition, this study provides comparative analysis on general behavior characteristics of friction pendulum system by comparing the result with that of the analysis on lead rubber bearing which possesses the same dynamic properties.

A Study on Fatigue Crack Growth Parameters for Fatigue Life Assessment based on Fracture Mechanics (파괴역학 기반 피로 수명 평가를 위한 피로 균열 진전 파라미터에 관한 연구)

  • Kim, Hyeon-Su;Park, Tae-Jong;Lee, Dong-Ju;Shin, Sang-Beom;Kim, Myung-Hyun
    • Journal of Welding and Joining
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    • v.35 no.1
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    • pp.61-67
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    • 2017
  • Recent studies on the fatigue assessment of high strength steel weld based on the fracture mechanics have frequently raised the problems related to the conservatism in the fatigue crack growth rate specified in the relevant design code. The purpose of this study is to evaluate the effect of the fatigue crack growth parameter on the fatigue life for the low carbon steel weld. In order to do it, the fatigue tests with the constant stress ratio were performed to evaluate the fatigue crack growth rate in the butt weld of SM490. And the fatigue crack growth parameters of the weld were evaluated in accordance with ASTM E647. From the comparative fatigue assessment results, it was found that the fatigue crack growth rate specified in the relevant design code was too conservative to estimate the residual fatigue life of welded structure. So, in order to get the more reliable results, it was recommended that the fatigue life estimation based on the fracture mechanics be performed with the fatigue crack growth parameter specified by test.

A Converging Approach on Investment Strategies, Past Financial Information, and Investors' Behavioral Bias in the Korean Stock Market (주식투자 전략, 과거 재무정보, 투자자의 행태편향에 대한 융합적 연구)

  • Koh, Seunghee
    • Journal of the Korea Convergence Society
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    • v.7 no.6
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    • pp.205-212
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    • 2016
  • This study attempts to empirically investigate if value strategy and momentum strategy could be improved by using past financial data such as ROE and PER in the Korean stock market. The study observes that both strategies which are refined by the portfolios consisting of companies with higher ROE/PER ratio show higher positive excessive returns than the traditional value strategy and momentum strategy. The study discusses that the excessive returns could be due to investors' behavioral biases such as conservatism, anchoring, confirmation, and herding by using convergent approach based on psychology theory. The results are not consistent with the efficient market hypothesis insisting investors' rational behavior.

Contribution of thermal-hydraulic validation tests to the standard design approval of SMART

  • Park, Hyun-Sik;Kwon, Tae-Soon;Moon, Sang-Ki;Cho, Seok;Euh, Dong-Jin;Yi, Sung-Jae
    • Nuclear Engineering and Technology
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    • v.49 no.7
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    • pp.1537-1546
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    • 2017
  • Many thermal-hydraulic tests have been conducted at the Korea Atomic Energy Research Institute for verification of the SMART (System-integrated Modular Advanced ReacTor) design, the standard design approval of which was issued by the Korean regulatory body. In this paper, the contributions of these tests to the standard design approval of SMART are discussed. First, an integral effect test facility named VISTA-ITL (Experimental Verification by Integral Simulation of Transients and Accidents-Integral Test Loop) has been utilized to assess the TASS/SMR-S (Transient and Set-point Simulation/Small and Medium) safety analysis code and confirm its conservatism, to support standard design approval, and to construct a database for the SMART design optimization. In addition, many separate effect tests have been performed. The reactor internal flow test has been conducted using the SCOP (SMART COre flow distribution and Pressure drop test) facility to evaluate the reactor internal flow and pressure distributions. An ECC (Emergency Core Coolant) performance test has been carried out using the SWAT (SMART ECC Water Asymmetric Two-phase choking test) facility to evaluate the safety injection performance and to validate the thermal-hydraulic model used in the safety analysis code. The Freon CHF (Critical Heat Flux) test has been performed using the FTHEL (Freon Thermal Hydraulic Experimental Loop) facility to construct a database from the $5{\times}5$ rod bundle Freon CHF tests and to evaluate the DNBR (Departure from Nucleate Boiling Ratio) model in the safety analysis and core design codes. These test results were used for standard design approval of SMART to verify its design bases, design tools, and analysis methodology.